If your AT&T camera is sending pictures inconsistently, one thing to try is to change the APN setting.
With the camera in setup mode:
- Press the Menu button.
- Scroll to the fourth menu tab.
- Scroll down to Diagnostic.
- Choose APN Setting.
- Enter the password, which is 123456 for 4G models and 1234 for 3G models.
- If you are using a Spartan SIM (solid white with the blue AT&T globe), the APN should be APNSP. If you are using an AT&T SIM (has some color on it), the APN should be either APNBR or APNBL. Choose whichever one it isn't.